As Ray Allen sat on the bench, chin encased in hand watching his teammates struggling in Game 7 of the Eastern Conference semifinals, it had to make you wonder if he was contemplating a sequel movie for Spike Lee, He Used to Have Game.

2008 NBA playoffs

Monday's game

Pistons even series with Celtics

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Rosen: Spurs turn it around

Rosen: Celtics' intensity pays off

Behrendt: D is key for Lakers

Kriegel: Time to toast Spurs?

Kahn: KG is heart of the Celtics

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Celtics put on road show

At the heart of this mysteriously uneven performance by the Boston Celtics in the 2008 NBA playoffs has been the rapid deterioration of Allen, inexorably one of the great shooters in NBA history. No team has ever won a championship after going seven games in the first two series of the playoffs, and yet the favored Celtics have done just that  winning Game 7 at home against the Cleveland Cavaliers after splitting the first six in the semifinals, just as they did against the Atlanta Hawks in the first round.

It's hard to fathom what they'll have left for the Detroit Pistons in the conference finals considering the Pistons have played just 11 games and have been resting for a week.

Most of the questions land at the flimsy ankles of Allen, who will be 34 in July. Ironically, he did come off the bench in the waning moments to sink a pair of free throws to clinch the victory over the Cavs on Sunday in Game 7. Despite his lack of productivity the rest of the game, it made sense to have Allen in the game, given that he is the seventh-most accurate foul-shooter in NBA history and is 32-of-33 in the playoffs.

Essentially, that's all he could be counted on for against the Cavs, and if you include Game 7 against the Hawks, it's even worse.

Allen has averaged 9.0 points over the past eight games  well under his career average of 21.1 points per game  and has made just 23 of 73 shots from the field (.315). Even more disastrous has been his long-range shooting. The second-most prolific 3-point shooter in league history behind Reggie Miller, he's just 5-of-29 over the past eight games  an anemic .172.

That's not to say he won't snap out of it. Surely he's had shooting slumps before  but never at this age and never on this stage. Only once before has his team made it to the conference finals, and he was sensational with the Milwaukee Bucks, averaging 25.1 points and making 48 percent of his 3-pointers in the playoffs. That just happened to be seven years and several ankle surgeries ago.

Nobody saw this coming, except maybe Seattle SuperSonics general manager Sam Presti, using Allen as the first element to strip and rebuild the Sonics. And yet, the approach the eight-time All-Star took to the move really was at the heart of Danny Ainge's ability to engineer the transformation of the Celtics. Allen eagerly accepted being traded from Seattle to Boston last June on draft day for Wally Szczerbiak, Delonte West and the rights to the fifth overall pick in the 2007 draft, forward Jeff Green.

Perhaps more importantly, Allen coaxed Kevin Garnett, who flatly rejected going to Boston before the Allen trade, into accepting a move there from Minnesota to join him and Paul Pierce as the most dynamic trio in the NBA. The result was a 66-win season, the best record in the NBA, and a 42-win improvement from a year ago that now stands as the greatest turnaround in history.

All three players saw their scoring averages drop as a point of team solidarity, with defense the focal point. Nonetheless, Allen had a solid season, averaging 17.4 points while shooting .445 from the field and .398 from 3-point range. He was even robbed in February of the Most Valuable Player award in the NBA All-Star game when he put on a sensational 14-point show during a three-minute span in the fourth quarter to help the East to victory.

Allen kept up his regular season scoring average in the first five games of the playoffs against the Hawks, but his shooting began to go south in Game 6, and he made just 2-of-13 from beyond the arc in the final two games of that series, closing with just 7 points in Game 7. Stunningly, he went scoreless in Game 1 against the Cavs, a first in his career, and he never got it together again in that series.

Now he faces fellow Connecticut alum and All-Star Richard Hamilton, one of the elite catch-and-shoot, mid-range gunners in the game. Tireless and one of the best conditioned athletes in any sport, Hamilton has always pushed Allen to the brink of exhaustion during the best of times in their rivalry. This series figures to be a different story unless Allen can somehow find a second wind and rediscover the confidence borne out of the 18,227 points he's scored in his NBA career.

Despite their extraordinary season and the superlative careers of Allen, Pierce and Garnett, the Celtics can't win unless the trio is hitting on all cylinders. Garnett will do his thing in a variety of ways, so that's not at issue. Pierce just put up a game for the ages with 41 points in Game 7 against Cleveland, so he is in top form. That leaves Allen and young point guard Rajon Rondo as the questions.

Sure, they'll play great team defense, but no better than the Pistons, who are in their sixth consecutive conference finals with four of five starters from that first group still intact. Analysts have been debating all season whether the Celtics would have the wherewithal to deal with the Pistons' experience and consistency in a seven-game series.

Now it appears even less likely, despite the Celtics having homecourt advantage again. And perhaps most vital to this cause will be Allen, who played Jesus Shuttlesworth from Lee's movie "He Got Game." Well, he had plenty of game as a high school star in the movie, and had even more through his real-life career at UConn and the first 12 years in the NBA.

Nobody has worked harder on his shooting on a daily basis than Allen. What we don't know is what he's got left in the tank. Neither do the Celtics, nor the Pistons. This could be just a passing slump. Or it might be the full-fledged meltdown of an aging jumpshooter with two years and about $35 million left on his contract.

If Ray-Ray responds, the Celtics will win the series. If he's done, so are they.